In fact, there are many disinfectants available for disinfecting sewage and wastewater. Chlorine dioxide is one of the more common ones. Its solubility in water is five times that of chlorine, and its oxidizing capacity is about 2.5 times that of chlorine gas. It is a strong oxidant and is also recognized as a highly efficient chlorine-containing disinfectant. How is it disinfecting? What are its characteristics?

The disinfection process using chlorine dioxide is as follows. The property of chlorine dioxide is not stable and can only be prepared on-site through a generator. It is mainly used in some small-scale chemical methods in the water treatment field. There are two situations, and these two generators can be considered as the most common ones!

1.The principle of using a composite chlorine dioxide generator. This principle mainly involves preparing chlorine dioxide through the reaction of sodium chlorate and hydrochloric acid (NaClO3 + 2HCl = ClO2 + 1/2Cl2 + NaCl + H2O). The stability of this reaction is 70℃, and the reactor is made of corrosion-resistant and temperature-resistant materials. It will react to form a mixture of chlorine dioxide and chlorine gas, which is then injected into the treated water through a water jet device for treatment!

2.This mainly explains the application of the composite chlorine dioxide generator. When used for disinfection, the dosage point of the disinfectant is usually after the filter. The dosage of effective chlorine is between 3 and 5 mg/L; however, if it is used for decolorization or to reduce COD values, it is better to add it before the addition point of other substances such as aluminum sulfate for coagulation, and the dosage depends on the water quality.

What are the Characteristics of Chlorine Dioxide Disinfection?

The main characteristic is that it only has an oxidizing effect but no chlorination effect. In this way, carcinogenic substances will not be produced. Chlorine dioxide is actually comparable to chlorine gas. However, when the NH3N concentration in the sewage is high, the amount of chlorine consumed will increase, but chlorine dioxide will not react with NH3, so the dosage does not need to be increased. Also, chlorine dioxide disinfection is not affected by pH, etc.

Of course, there is one thing we need to understand: it is disinfection using chlorine-containing disinfectants. It is very important to monitor the content of chlorine-containing disinfectants in water in real time through the RCl900 Total Residual Chlorine Online Analyzer, in order to control the total residual chlorine content in the water within a safe range!